There has been much recent interest and effort directed to developing and using microfluidic devices. Microfluidic devices have already found useful application in printing devices and in so-called “lab-on-a-chip” devices, wherein complex chemical and biochemical reactions are carried out in microfluidic devices. The very small volumes of liquid needed for reactions in such a system enables increased reaction response time, low sample volume, and reduced reagent cost. It is anticipated that a myriad of further applications will become evident as the technology is refined and developed.
A significant factor in the design of a microfluidic device is the resistance to fluid movement imposed by contact of fluid with surfaces in the microscopic channels of the device. In order to overcome this resistance, higher fluid pressures are required within the device. In turn, fluid flow rates through the device may be limited by the amount of pressure that can be tolerated by the device or the process that the device supports. In addition, pressure losses through microscopic flow channels may vary greatly due to the characteristics of surfaces in the flow channel.
What is needed in the industry is a microfluidic device with fluid flow channels having predictable and optimal levels of resistance to fluid flow.